The Effect of Continuous Low Dose Creatine Supplementation on Force, Power, and Total Work

2000 ◽  
Vol 10 (3) ◽  
pp. 235-244 ◽  
Author(s):  
Darren G. Burke ◽  
Shawn Silver ◽  
Laurence E. Holt ◽  
Truis Smith-Palmer ◽  
Christopher J. Culligan ◽  
...  
Keyword(s):  
Athletic Training ◽  
Short Duration ◽  
Power Output ◽  
High Intensity ◽  
Peak Power ◽  
Low Dose ◽  
Creatine Supplementation ◽  
Peak Power Output ◽  
Total Work ◽  
Force Output

Dietary supplementation (SUP) has become a significant part of athletic training. Studies indicate that creatine (Cr) can enhance short-duration, high-intensity activities. This study examined the effect of 21 days of low dose Cr SUP (~7.7 g/day) and resistance training on force output, power output, duration of mean peak power output, and total work performed until fatigue. A double-blind protocol was used, where an individual, who was not part of any other aspect of the study, randomly assigned subjects to creatine and placebo groups. Forty-one male university athletes were randomly assigned to either Cr (n= 20) or placebo (n = 21) SUP. On the first and last day of the study, subjects were required to perform concentric bench press movements until exhaustion on an isokinetic dynamometer. The dynamometer was hard-wired to a personal computer, which provided force, velocity, and duration measures. Force and power output until fatigue, were used to determine total work, force-time, and power-time relationships. ANOVA results revealed that the Cr subjects performed more total work until fatigue, experienced significantly greater improvements in peak force and peak power, and maintained elevated mean peak power for a longer period of time. These results indicate that Cr SUP can significantly improve factors associated with short-duration, high-intensity activity.

Effect of oral creatine supplementation on power output and fatigue during bicycle ergometry

1995 ◽  
Vol 78 (2) ◽  
pp. 670-673 ◽  
Author(s):  
W. H. Cooke ◽  
P. W. Grandjean ◽  
W. S. Barnes
Keyword(s):  
Power Output ◽  
High Intensity ◽  
Peak Power ◽  
Creatine Supplementation ◽  
Total Work ◽  
Fatigue Index ◽  
Bicycle Ergometry ◽  
Double Blind ◽  
Mean Values ◽  
Time To Peak

Our purpose was to determine the effect of oral creatine supplementation on exercise performance during high-intensity short-duration bicycle sprinting. Power output was recorded for 12 healthy untrained males (age 24.08 +/- 0.53 yr, weight 81.22 +/- 1.32 kg) before and after 5 days of creatine (n = 6) or placebo (n = 6) supplementation. A double-blind research design was employed. Subjects performed maximal sprints against a constant load (111.8 N) for 15 s. Each one-half pedal revolution was magnetically counted, and subsequent measurements of peak power, time to peak power, total work, and the fatigue index were digitized and stored on disk. Mean values for peak power, time to peak power, total work, and fatigue index were 958.01 +/- 40.66 W, 4.09 +/- 0.82 s, 11.28 +/- 0.46 kJ, and 32.1 +/- 1.58% decline from peak power, respectively. No significant differences were observed within or between groups before or after supplementation for any of the mechanical parameters measured (P > 0.05). These findings suggest that oral creatine supplementation does not positively affect power output or fatigue during continuous high-intensity bicycle exercise in untrained men.

The Influence of Recovery Duration on High-Intensity Exercise Performance After Oral Creatine Supplementation

1997 ◽  
Vol 22 (5) ◽  
pp. 454-467 ◽  
Author(s):  
William H. Cooke ◽  
William S. Barnes
Keyword(s):  
Power Output ◽  
High Intensity ◽  
Peak Power ◽  
Creatine Supplementation ◽  
Cycle Ergometer ◽  
Peak Power Output ◽  
Significant Group ◽  
Before And After ◽  
Maximal Peak ◽  
Male Subjects

The purpose of this study was to determine the effects of creatine supplementation on the ability to reproduce and maintain a high percentage of peak power output during the second of two bouts of high-intensity cycle sprinting following four different recovery intervals. Eighty healthy, active male subjects were randomly assigned to one of two groups (creatine or placebo) and one of four recovery intervals (30, 60, 90, or 120 s). Two maximal cycle ergometer sprints, separated by the assigned recovery interval were performed before and after a 5-day supplementation protocol in which 20 g/day of creatine (plus 4 g/day glucose) or 24 g/day glucose placebo were ingested by subjects from creatine and placebo groups, respectively. Maximal peak power output (PP) and the absolute time to fatigue (TTF) were compared pre- versus postsupplementation. No significant group interactions were noted in this study. Specifically, creatine supplementation had no effect on subjects' ability to reproduce or maintain a high percentage of PP during the second bout of exercise. Key words: ergogenic aids, cycle ergometry, short-term fatigue

Reducing Anxiety and Anxiety Sensitivity With High-Intensity Interval Training in Adults With Asthma

2020 ◽  
Vol 17 (8) ◽  
pp. 835-839
Author(s):  
Carley O’Neill ◽  
Shilpa Dogra
Keyword(s):  
Anxiety Sensitivity ◽  
Power Output ◽  
High Intensity ◽  
Peak Power ◽  
Interval Training ◽  
Peak Power Output ◽  
Sensitivity Index ◽  
High Intensity Interval Training ◽  
High Intensity Interval ◽  
The Impact

Background: Low- and moderate-intensity exercise training has been shown to be effective for reducing general anxiety and anxiety sensitivity among adults with asthma. Exercise frequency and intensity have been shown to play an integral role in reducing anxiety sensitivity; however, less is known about the impact of high-intensity interval training (HIIT) on anxiety in adults with asthma. Methods: A 6-week HIIT intervention was conducted with adults with asthma. Participants completed HIIT (10% peak power output for 1 min, 90% peak power output for 1 min, repeated 10 times) 3 times per week on a cycle ergometer. Preintervention and postintervention assessments included the Anxiety Sensitivity Index-3 and the Body Sensations Questionnaire. Results: Total Anxiety Sensitivity Index-3 (PRE: 17.9 [11.8]; POST 12.4 [13], P = .002, Cohen d = 0.4, n = 20) and Body Sensations Questionnaire (PRE: 2.4 [1.0]; POST: 2.0 [0.8], P = .007, Cohen d = 0.3) improved from preintervention to postintervention. Conclusion: A 6-week HIIT intervention leads to improved anxiety among adults with asthma. Future research should determine the impact of HIIT among adults with asthma with clinical anxiety.

Muscle performance and enzymatic adaptations to sprint interval training

1998 ◽  
Vol 84 (6) ◽  
pp. 2138-2142 ◽  
Author(s):  
J. Duncan MacDougall ◽  
Audrey L. Hicks ◽  
Jay R. MacDonald ◽  
Robert S. McKelvie ◽  
Howard J. Green ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Succinate Dehydrogenase ◽  
Power Output ◽  
Peak Power ◽  
Citrate Synthase ◽  
Interval Training ◽  
Peak Power Output ◽  
Sprint Interval Training ◽  
Total Work ◽  
Before And After

Our purpose was to examine the effects of sprint interval training on muscle glycolytic and oxidative enzyme activity and exercise performance. Twelve healthy men (22 ± 2 yr of age) underwent intense interval training on a cycle ergometer for 7 wk. Training consisted of 30-s maximum sprint efforts (Wingate protocol) interspersed by 2–4 min of recovery, performed three times per week. The program began with four intervals with 4 min of recovery per session in week 1 and progressed to 10 intervals with 2.5 min of recovery per session by week 7. Peak power output and total work over repeated maximal 30-s efforts and maximal oxygen consumption (V˙o 2 max) were measured before and after the training program. Needle biopsies were taken from vastus lateralis of nine subjects before and after the program and assayed for the maximal activity of hexokinase, total glycogen phosphorylase, phosphofructokinase, lactate dehydrogenase, citrate synthase, succinate dehydrogenase, malate dehydrogenase, and 3-hydroxyacyl-CoA dehydrogenase. The training program resulted in significant increases in peak power output, total work over 30 s, andV˙o 2 max. Maximal enzyme activity of hexokinase, phosphofructokinase, citrate synthase, succinate dehydrogenase, and malate dehydrogenase was also significantly ( P < 0.05) higher after training. It was concluded that relatively brief but intense sprint training can result in an increase in both glycolytic and oxidative enzyme activity, maximum short-term power output, andV˙o 2 max.

Acute High-Intensity Interval Training Improves Tvent and Peak Power Output in Highly Trained Males

2002 ◽  
Vol 27 (4) ◽  
pp. 336-348 ◽  
Author(s):  
Paul B. Laursen ◽  
Michelle A. Blanchard ◽  
David G. Jenkins
Keyword(s):  
Oxygen Uptake ◽  
Power Output ◽  
High Intensity ◽  
Peak Power ◽  
Ventilatory Threshold ◽  
Interval Training ◽  
Peak Power Output ◽  
Control Group ◽  
High Intensity Interval Training ◽  
High Intensity Interval

This study examined the effects of four high-intensity interval-training (HIT) sessions performed over 2 weeks on peak volume of oxygen uptake [Formula: see text] the first and second ventilatory thresholds (VT1, VT2) and peak power output (PPO) in highly trained cyclists. Fourteen highly trained male cyclists [Formula: see text] performed a ramped cycle test to determine [Formula: see text]VT1, VT2, and PPO. Subjects were divided equally into a HIT group and a control group. The HIT group performed four HIT sessions (20 × 60 s at PPO, 120 s recovery); the [Formula: see text] test was repeated < 1 wk after the HIT program. Control subjects maintained their regular training program and were reassessed under the same timeline. There was no change in [Formula: see text] for either group; however, the HIT group showed a significantly greater increase in VT1 (+22% vs. −3%), VT2 (+15% vs. −1%), and PPO (+4.3 vs. −4%) compared to controls (all P < .05). This study has demonstrated that HIT can improve VT1, VT2 and PPO, following only four HIT sessions in already highly trained cyclists. Key words: cycling, cyclists, heart rate, oxygen uptake, short-term training, ventilatory threshold

Measuring Fatigue Relative to Peak Power Output during High-Intensity Cycle Sprinting

1997 ◽  
Vol 68 (4) ◽  
pp. 303-308 ◽  
Author(s):  
William H. Cooke ◽  
Chad A. Whitacre ◽  
William S. Barnes
Keyword(s):  
Power Output ◽  
High Intensity ◽  
Peak Power ◽  
Peak Power Output

Metabolic and hormonal responses to isoenergetic high-intensity interval exercise and continuous moderate-intensity exercise

2014 ◽  
Vol 307 (7) ◽  
pp. E539-E552 ◽  
Author(s):  
Jonathan M. Peake ◽  
Sok Joo Tan ◽  
James F. Markworth ◽  
James A. Broadbent ◽  
Tina L. Skinner ◽  
...  
Keyword(s):  
Power Output ◽  
High Intensity ◽  
Peak Power ◽  
Moderate Intensity ◽  
Peak Power Output ◽  
Total Serum ◽  
Plasma Norepinephrine ◽  
Moderate Intensity Exercise ◽  
Counterregulatory Hormones ◽  
High Intensity Interval

This study investigated the effects of high-intensity interval training (HIIT) vs. work-matched moderate-intensity continuous exercise (MOD) on metabolism and counterregulatory stress hormones. In a randomized and counterbalanced order, 10 well-trained male cyclists and triathletes completed a HIIT session [81.6 ± 3.7% maximum oxygen consumption (V̇o2 max); 72.0 ± 3.2% peak power output; 792 ± 95 kJ] and a MOD session (66.7 ± 3.5% V̇o2 max; 48.5 ± 3.1% peak power output; 797 ± 95 kJ). Blood samples were collected before, immediately after, and 1 and 2 h postexercise. Carbohydrate oxidation was higher ( P = 0.037; 20%), whereas fat oxidation was lower ( P = 0.037; −47%) during HIIT vs. MOD. Immediately after exercise, plasma glucose ( P = 0.024; 20%) and lactate ( P < 0.01; 5.4×) were higher in HIIT vs. MOD, whereas total serum free fatty acid concentration was not significantly different ( P = 0.33). Targeted gas chromatography-mass spectromtery metabolomics analysis identified and quantified 49 metabolites in plasma, among which 11 changed after both HIIT and MOD, 13 changed only after HIIT, and 5 changed only after MOD. Notable changes included substantial increases in tricarboxylic acid intermediates and monounsaturated fatty acids after HIIT and marked decreases in amino acids during recovery from both trials. Plasma adrenocorticotrophic hormone ( P = 0.019), cortisol ( P < 0.01), and growth hormone ( P < 0.01) were all higher immediately after HIIT. Plasma norepinephrine ( P = 0.11) and interleukin-6 ( P = 0.20) immediately after exercise were not significantly different between trials. Plasma insulin decreased during recovery from both HIIT and MOD ( P < 0.01). These data indicate distinct differences in specific metabolites and counterregulatory hormones following HIIT vs. MOD and highlight the value of targeted metabolomic analysis to provide more detailed insights into the metabolic demands of exercise.

Abstract P134: Preliminary Data: Dietary Nitrate Supplementation Does Not Extend Dry Static Apnea Or Wingate Performance

Circulation ◽  
2021 ◽  
Vol 143 (Suppl_1) ◽  
Author(s):  
Colin Carriker ◽  
Phillip Armentrout ◽  
Sarah Levine ◽  
James Smoliga
Keyword(s):  
Power Output ◽  
Preliminary Data ◽  
Repeated Measures ◽  
Peak Power ◽  
Hold Time ◽  
Wingate Test ◽  
Peak Power Output ◽  
Breath Hold ◽  
Dietary Nitrate ◽  
Nitrate Supplementation

Introduction: Previous studies have examined dietary nitrate supplementation and its effects on dry static apnea, and peak power. Dietary nitrate supplementation has been found to increase maximal apnea and peak power output. The purpose of this study was to determine the effects of beetroot juice on dry static apnea and Wingate performance. Hypothesis: Dietary nitrate will improve maximal breath hold time and peak power output. Dietary nitrate will improve tolerance to CO2, thereby improving maximal breath hold time and anaerobic capacity. Methods: In a randomized, double-blind, counterbalanced study, five healthy males (20.4±0.89 years) visited the lab on 3 separate occasions each separated by one week. Visit 1 served as a Wingate and breath hold familiarization visit. Prior to visits 2 and 3 participants were instructed to drink a beverage either a placebo (negligible nitrate content, PL) or dietary nitrate rich beverage (12.4 mmol nitrate, NIT) during the 4 days leading up to their next visit. Visits 2 and 3 consisted of two submaximal breath holds (80% of maximal determined during visit 1), with 2 minutes of rest between and three minutes of rest preceding the final breath hold for maximal duration. Finally, participants completed a standardized 10-minute warmup on the cycle ergometer before completing a 30-second maximal effort Wingate test. Results: A linear mixed effects model was used to determine whether treatment (NIT vs. PL) was associated with differences in VCO2 or PetCO2. Time (0, 10, 20, 30 min post-breath hold) and Treatment both served as repeated measures. Models were developed using multiple repeated measures covariance matrix structures, and the model with the lowest AIC was chosen as the final model. The interaction between time and treatment was included in the original models, and was removed if it was not statistically significant. Time was a statistically significant factor for VCO2 and PetCO2 (p < 0.001). Treatment, and the Time x Treatment interaction was not significant for either variable. No differences between NIT and PL were observed during the Wingate test for either time to peak power (5.02±2.45 and 6.2±2.43 sec, respectively) or maximal power (9.73±1.01 and 9.72±1.03 watts/kg, respectively) and fatigue index (49.42±14.98 and 47.30±6.99 watts/sec, respectively). Conclusion: Preliminary data indicates that in a general population four days of dietary nitrate supplementation may not improve breath hold time, tolerance to carbon dioxide in the lungs, or Wingate performance.

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